I finally got the title straightened out on my 1960 Imperial so I wrote off to Stellantis to get the build card and dealer info. I got this reply from Danielle. I know it's not that important for 300s since the club has the info but lots of us have other Mopars. Can't wait to see what happens.
Thank you for contacting the Stellantis Historical Services. We have exciting news to share. The archives will be moving to a new location by the end of this year. Our new facility allows us the opportunity to better serve our loyal customers. With this said, we will be temporarily shutting down our services to focus on our move. We hope to resume our services the beginning of next year. We will save your request and begin sending build record orders in January 2024 by email. Your patience is appreciated during this time.